Can you tell me about the vibrant blue glaze on the small vase? Why is it so much brighter than the other pots? Do you know about the firing process?
Sure. The body of the vessel was decorated with black pigment and then covered with a transparent turquoise glaze likely colored with copper oxides.
Black and turquoise ware is typical of Raqqa ceramics from this period as potters took advantage of the fritware body to provide a white background and the stability of the black pigment to execute a crisp design. Other vessels in this display are rejects or mistakes that, therefore, do not show the same level of finish.